Prevention of rust



Patented Dec. 12, 1950 PREVENTION or nUsr Franklin M. Watkins, mossmodr, mama to Sinclair Refining Company, a corporation of Maine New York, N. 1.,

No Drawing. Applicationseptemberxzfilildi,

SerialNo. 776,415.

7 Claims. I

My invention is concerned with a method for preventing or retarding especially rusting due to water dissolved or entrained in or settled from petroleum oils, including especially gasoline, kerosene and fuel oils. The method is particularly valuable as applied to prevent rustingin Pip lines. r

Rust frequently occurs in pipe lines, storage tanks, etc. and even in automotive and similar equipment because of traces of moisture inevit-. ably present iii the fuel or lubricant. Gasoline and kerosene, for example, as they leave the reflnery are usually free of occluded moisturebut they may contain as much as (HIDE-0.01% dissolved moisture. Part of this fdissolved moisture separates when the oil is chilled in a storage tank, for instance, and settles as a separate liquid phase beneath the main body of the oil.

Water may also enter oil handling systems along with air through partially filled tanks provided with breather devices. As such a tank cools, for example'at night, the contents contract and air laden with moisture enters. This moisture condenses on the walls of the tank, settles to the bottom and dried air is expelled whenthe conduced by reaction of sulfuric acid-treated petroleum oil and cyclohexylamine, which itself may be readily produced by any one of several standard procedures well known in the art. In the reaction with the sulfuric acid-treated petroleum oil, the cyclohexylamine should preferably be used in approximately the quantity called for by theory as determined by the acid number of the tents of the tank again warinfup as from the heat of thesun the next day. As will be readily appreciated,"repetition of this cycle eventually leaves appreciable amounts of water at the bottom fol the tank. f

Although several methodshave been proposed for preventing rusting in product handling systems, each of these has rather obvious shortcomings. I One method, for example; involves drying of the product, as gasoline, by absorption on dehydrated alumina before the'product is pumped into pipe lines. Another method involves the inplied to inhibit rusting in pipelines is frequently 1 decomposed by the action of oxidizingagents present in some crude oils. Hydrogen is, quickly lost from vented storage tanks while water soluble inhibitors are lost when they settletothe bottom of storage tanks and are drawnoii'. Completely water solubleinhibitors are further deflcient in many instances in notafiording protectionintheoilphase. A ,g a

The rust-inhibiting agent employed the pracacid oil. In a typical small scale preparation of aconcentrate of the amine sulfonate, 100 grams of an acid-treated oil containing .0239 mole of sulfonic acid and 2.37 grams of cyclohexylamine are stirred for two hours during which period the temperature rises from about F. to about F. "The reaction mixture is cleared of a slight haze by filtration and the filtrate diluted with neutral oil to give'a blend analyzing about 10% sulfonate'.

In such a runas above the acid oil reacted with the cyclohexylamine may test about as follows:

Gravity, API 29.4 Viscosity at 100 F. SUS 205 .Viscosity'at 210 F. SUS 47.2 Acid:number 13.4

particular acid oil was prepared by treating a Mid-Continent neutral oil with successive dumps of oleum, a total of pounds of oleum ing property of the s'ulfonate I have found the use of 10% concentrates advantageous.

Concentrates prepared as described find wide application. Thuspin addition to being useful in inhibiting rusting in storage tanks, pipe lines,

etcgitheymay beblended with oils of suitable characteristics to provide lubricating compositions which will retard, the corrosion of iron and steel surfaces with which they come into contact. In such an application, as little as 5 to as much as 400-500 pounds of a concentrate may be used per 1,000 barrels of oil, the exact amount depending upon the degree of protection required and other factors including the extent of solubility of the sulfonate in the particular base oil, the viscosity of the base oil, etc. Highly effective slushing and needle oils can be prepared by blending concentrates with oils conventionally used in slushing and needle oil manufacture. Such oils are applied to'clean metal surfaces as by spraying, brushing or dipping to protect the surface from corrosion by atmospheric moisture or accidental moisture spray. The formula of a typical lubricating composition which is also useful for slushing purposes is given below:

Tn this composition, the turpentine-Pass reaction product functions as an antioxidant and bearing corrosion inhibitor, while the reaction product of diamylphenol and P205 increases film strength and also supplements the rust-inhibiting action of the sulfonate. The rust-inhibiting action of the diamylphenol-PzOs product is altogether different from that of the sulfonates;

This product is quite effective in preventing rusting in salt spray but unlike the sulfonates it is ineffective under the conditions of the conventional humidity cabinet test. As the pour depressor in the composition any one of the several commercial products such as Santopour, for example, may be used.

Objects or articles susceptible to attack by moisture with resultant corrosion, and which may be treated with oil-base compositions prepared according to my invention include, for example, accurately machined parts such as piston rings, pump plungers, etc., castings such as steel castings, which are frequently stored in the open for long periods, idle machinery, storage drums, tools and the like.

I have found that the sulfonate concentrate is not satisfactory for use in turbine oils as an antirust agent because of the emulsifying properties poses, a polished mild steel strip is suspended in a beaker fitted with a mechanical stirrer and containing 350 mls. of the test blend. The blend is stirred for 30 minutes after which 50 mls. thereof is removed and 30 mls. of distilled water substituted. Stirring is continued for 48 hours and the strip then inspected for rust.

The appended table compares the effectiveness of monocyclohexylamine mahogany sulfonate in the described test with other amine mahogany suli'onates and representative metal mahogany 1 Of a concentrate containing 10% sulfonate. 2 Rust rating:

A=no rust on strip.

B+=up to 5% of surface rusted. B =525% of surface rusted. C=2550% of surface rusted. D=5075% of surface rusted. E=-l00% of surface rusted.

I claim:

1. The method of inhibiting the rusting of iron and steel surfaces which comprises maintaining a suitably concentrated petroleum oil distillate solution of cyclohexylamine mahogany sulfonate in contact with such surfaces, said petroleum oil distillate being selected from the group consisting of gasoline, kerosene and fuel oil.

2. A petroleum oil distillate base composition efiective for retarding rusting of iron and steel surfaces which comprises cyclohexylamine mahogany sulfonate as an active rust-inhibiting component, said petroleum oil distillate being selected from the group consisting of gasoline, kerosene and fuel oil.

3. A petroleum oil distillate to which a rustinhibiting property has been imparted by the incorporation of an effective concentration of cyclohexylamine mahogany sulfonate, said petroleum oil distillate being selected from the group consisting of gasoline, kerosene and fuel oil.

4. Gasoline to which a rust-inhibiting property has been imparted by the' incorporation of an effective concentration of cyclohexylamine mahogany sulfonate.

5. Kerosene to which a rust-inhibiting property has been imparted by the incorporation of an effective concentration of cyclohaxylamine mahogany sulfonate.

6. Fuel oil to which a rust-inhibiting property has been imparted by the incorporation of an effective concentration of cyclohexylamine mahogany sulfonate.

7. Method of preventing the rusting of pipe lines, storage tanks, and other petroleum refinery equipment which comprises incorporating in the petroleum oil distillate introduced into the equipment an effective amount of cyclohexylamine mahogany sulfonate, said petroleum oil 6 distillate being selected from the group consisting of gasoline, kerosene and fuel oil.

FRANKLIN M. WATKINS.

REFERENCES CITED 6 UNITED STATES PATENTS Number Name Date Taylor Nov. 10, 1936 Murphy Aug. 2. 1938 Sloan Nov. 2, 1943 Wasson et al June 11, 1946 Schwartz Dec. 17, 1946 Zlmmer et a1. July 13, 1948 

1. THE METHOD OF INHIBITING THE RUSTING OF IRON AND STEEL SURFACES WHICH COMPRISES MAINTAINING A SUITABLY CONCENTRATED PETROLEUM OIL DISTILLATE SOLUTION OF CYCLOHEXYLAMINE MAHOGANY SULFONATE IN CONTRACT WITH SUCH SURFACES, SAID PETROLEUM OIL DISTILLATE BEING SELECTED FROM THE GROUP CONSISTING OF OF GASOLINE, KEROSENE AND FUEL OIL. 